This allows the setting of an ansible osa_disable_serial variable
that drops in a config to set all of the serial settings to 100%
to disable throttling. The exception being keystone as it has a
race condition that prevents it. The default is 'false' and can
be set in the MNAIO_ANSIBLE_PARAMETERS var before running the
build.sh script.
Change-Id: I5850d882d465b7ef10b317076bb135934f1ceba2
Closes-Bug: 1752475